cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

A081368 Next n digits of e, base of the natural logarithms.

Original entry on oeis.org

2, 71, 828, 1828, 45904, 5235360, 2874713, 52662497, 757247093, 6999595749, 66967627724, 76630353547, 5945713821785, 25166427427466, 391932003059921, 8174135966290435, 72900334295260595, 630738132328627943
Offset: 1

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Author

Michael Joseph Halm, Apr 20 2003

Keywords

Comments

Any zeros that immediately follow a term of this sequence are appended to that term of the sequence.

Examples

			a(2) = 71 because the second and third digits of e are 7 and 1.
		

References

  • M. J. Halm, More Sequences, Mpossibilities 83, April 2003.
  • C. A. Pickover, Wonders of Numbers, p. 302
  • C. Pickover, Mazes for the Mind, St. Martin's Press, NY, 1992, p. 350.
  • Clifford A. Pickover, A Passion for Mathematics, Wiley, 2005; see p. 65.

Crossrefs

A267325 Next n digits of sqrt(2).

Original entry on oeis.org

1, 41, 421, 3562, 37309, 504880, 1688724, 20969807, 856967187, 5376948073, 17667973799, 73247846210, 7038850387534, 32764157273501, 384623091229702, 4924836055850737, 21264412149709993, 583141322266592750, 5592755799950501152, 78206057147010955997
Offset: 1

Views

Author

Ilya Gutkovskiy, Jan 13 2016

Keywords

Examples

			a(2) = 41 because the second and third digits of sqrt(2) are 4 and 1.
		

Crossrefs

Programs

  • Magma
    [Floor(Sqrt(2)*10^(n*(n + 1)/2 - 1)) mod (10^n): n in [1..30]]; // Vincenzo Librandi, Feb 15 2016
    
  • Mathematica
    Table[Mod[Floor[Sqrt[2] 10^(n ((n + 1)/2) - 1)], 10^n], {n, 1, 20}]
    Table[Floor[10^(-1 + (n (1 + n))/2) Sqrt[2]] + Ceiling[-(Floor[10^(-1 + (n (1 + n))/2) Sqrt[2]]/10^n)] 10^n, {n, 1, 20}]
    With[{x=20},FromDigits/@TakeList[RealDigits[Sqrt[2],10,(x(x+1))/2] [[1]], Range[x]]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 04 2019 *)
  • PARI
    a(n) = lift(Mod(floor(sqrt(2)*10^(n*(n + 1)/2 - 1)), 10^n)); \\ G. C. Greubel, Oct 07 2018

Formula

a(n) = floor(sqrt(2)*10^(n*(n + 1)/2 - 1)) mod (10^n).
Showing 1-2 of 2 results.